Wakefield's Classic Car Talk

automobile metal repair and panel welding

Bruce — Wed, 30 Jun 2010 18:56:42 +0000

I was talking to a nice gentlemen recently who had read my rust article. He wanted to know if the guys who had redone his Camaro did it correctly. I asked him if he had any photos of the resto process. Well in fact he didn’t. But he described what he had seen when he visited the restoration process. I had a few follow up questions that he couldn’t answer, bottom line I can not stress enough how important progress photos of your restoration or car build are. Photos are the only way to document what was done to your car.
Moving forward I think this guy has some interesting questions about how to properly repair or restore the body on any car.
Let me start this explanation by saying that I was learning the body trade in the late 50s. This was an interesting time in the evolution of automotive metal work in the new car construction. Going back to the early beginning of car construction on assembly lines The sheet metal used in body panel stampings was much thicker than it is today. Since the late 20’s and early 30’s where it was not uncommon to see sheet metal on cars that was 10 and 12 gauge metal. Most body panels were 14 gauge. Connecting body panels was achieved by fixing the steel panels to a wooden body skeleton with nails and or screws. Accident damage was repaired by hammering out the dent and metal working the area until it could be filed smooth. The addition of Lead applied to the metal provided another way to smooth the panel before painting. Lead soon became an accepted repair method. Experienced leaders also became body artists in customizing metal bodies. When I came on to the car scene in the late 50’s sheet metal was much thinner so the hammer and dolly technique was an art, too much was a bad thing. Wood skeletons were gone. Body panels were welded together and exterior seams were leaded. The practice of attaching panels was being done by the form of “spot welding” Somewhere along in the late 40’s fiberglass car bodies were “experimental” In the early 50’s “Bondo” a plastic body filler was making it’s debut, and has been misused ever since.
Not to say that new technology hasn’t improved many aspect of automotive body work, but if we take a look at the old school methods we might get an understanding of what works and why. Going on the premise that back in the 50’s a body repair was done to be permanent. Today insurance companies consider an auto body repair permanent if it lasts 3.5 years. Dissimilar materials rarely stick to each other forever. Plastic body filler isn’t permanent, over time it lifts, puckers, shrinks, or peels. When was the last time you saw lead crack chip or peel on an auto repair. Enough said about smoothing body work techniques, remember “less is best.”
That brings us to the last tidbit of metal body work, or the art of welding and panel fitment or replacement. There should be no argument that the best repair to a metal car body is the exact body panel replacement attached in the exact method done by the factory. Lets say you have a rusted out quarter panel on a 1965 Mustang Coupe. In my opinion the best way to fix the rust is to remove the complete quarter panel, call the factory and order a OEM quarter panel and attached it with spot welds following the factory weld map, the roof seam gets lead and the trunk seams get a touch of sealer. Well you and I know that there are a few flaws in that procedure, primarily it is next to impossible to get OEM panels for older cars. So we are stuck with aftermarket panels that may not be the same gauge or of the same stamping quality of OEM panels. Even when working with complete aftermarket panels they can be still be attached just like the factory did it. Often we find that a lot of shops don’t have the same spot welding equipment as the factory. Consequently, other welding methods are and can be used. Bear in mind that the more heat that is applied to a metal panel the more “oxidation” occurs. Yep heat causes metal to oxidize. Isn’t the rust or “oxidation” the reason we are doing this in the first place? Remember in the welding repair process you will need to assure yourself that where heat was applied to weld the metal, you are able to clean up the metal and treat it so that the oxidation process is stopped or slowed as much as possible.
What if you have to repair metal and no complete panels are available, what then? Well this is where many opinions enter into the “what’s right, what’s wrong” arena. Many body guys think that butt welding replacement panels in is the only proper way to go. Others still use a “lap” seam to put partial panels on existing sheet metal. First let me say that butt welding eliminates the pocket between two panels that traps moisture and creates rust. But I must say it takes a very skillful welder to butt weld a big patch panel into existing sheet metal without causing a lot of distortion. The more distortion, the more body filler is needed, now you have a whole different set of problems. Remember when it comes to any filler “less is best” As an alternative is the overlay of panels, as we discussed this method put two pieces one on top of the other using a 1/2 inch lap seam. The lap seam gives moisture a place to start oxidation. If you can seal both sides of the seams you will slow the possibility of oxidation occurring. Don’t forget that the factory uses a type of “lap joint” when they spot weld panels together. When performing a lap weld on an external panels I will always sweat the seam with lead when the welding is complete. Lead goes a long way to “seal” the lap joint. Bottom line either method can work well, both methods have pluses and minuses, sometimes you just have to trust the advice of the guy doing your work. Document it with photos.
Well we have looked at spot welds and the types of welds but we haven’t discussed the type of welding equipment. Whether it is electric stick or wire feed, Mig or Tig, or gas and stick, good results can be had by any experienced welder with any choice of welding process. One thing to be mindful of in the “good old days” we worked on body panels with the “less heat” approach. Braze was one such method that used less heat than arc or gas welding. When we were finished brazing a panel it was most always smoothed with lead before painting. I don’t ever remember problems when doing this type of repair. In recent work we notice that the plastic fillers have a tendency to “lift” or separate from braze material over time. This mystery of separation, seems to be due to the flux residue in the brazing process. So don’t use plastic filler over a brazed seam or joint. If you lead the braze first then apply the plastic filler I don’t think you will have a problem with “lifting”

Hot Rod wiring do’s and don’ts

Bruce — Wed, 23 Jun 2010 00:00:25 +0000

Are you building your dream car or are you contemplating buying a custom one of a kind car that was built by someone else? I have bought a few custom built cars over the years. Many of these car builds were done by “professional” builders. Others were done by guys just building their dream machine. For me many of them had one big mistake in common.You would think with all the very nice after market wiring kits out there rewiring an old car or building a new one would be easy and without any mistakes. Well from my perspective a very common simple, overlooked problem plagues many “one off” builds. Even cars built by “big time” builders.

Has this every happened to you? You are driving down the road in your custom ride. It’s got a super paint job, it has an awesome interior, a thunderous engine, and a head turning sound. You’re crusin, your getting looks and “thumbs up” Your car suddenly quits, dead. You are sitting there thinking “what the the heck happened?” After a little help and advice from bystanders watching you ponder your problem under the hood of your ride. You think “the electric fuel pump isn’t working” Somewhere you come up with a test light and discover you have no “power” at the pump. Well all you have to do now is look at the “fuel pump” fuse. “holly crap where is the fuse block?”

Well you can bet the fuse block is in the car somewhere, but where? I’ve been there, most builders put fuse blocks in a very logical place. Then build the care around it, hiding the fuses from plain sight. If you didn’t build the car you probably didn’t get any instructions on how to access the fuses. Finding the fuse block can be a nightmare. Once located seeing, checking, or removing a fuse can only be accomplished by a contortionist.

If you are building a car, spend a lot of time contemplating the location for your fuse block. If you buy a custom built car ask and document the location of fuses, relays, and wire looms. Troubleshooting an electrical problem with poorly placed fuses and wiring can be a nightmare. If a wiring diagram didn’t come with your custom build see if you can “pick the brain” of the builder, take notes. If you can’t trace the build history, well good luck.

Sooner or later you will have to check a fuse. If “Murphy” has anything to do with the timing for a fuse check, it will be at a time and place that will have you exclaiming “who put it there?”

Hello

Bruce — Tue, 22 Jun 2010 14:35:21 +0000

Hello Everyone. I will be posting soon!

72 Mustang

1955, 1956, 1957, Chevy rust: where to look

Bruce — Sun, 20 Jun 2010 18:10:55 +0000

Rust is the biggest problem with all metal bodied cars. The Tri-five Chevys are now 50 plus years old, there is going to be rust. Or there is going to have been rust repaired.

Rust! Oh my!

For the 55, 56, and 57 Chevys there are always “places” where rust will show up. We can typically see rust on the exterior surfaces. Front fenders above the headlights, front fenders on the lower back corner just in front of the door, on the lower edges of the doors, rocker panels, rear quarter panels on the lower edge just in front or just aft of the wheel well opening. In the last few years there has been an increase in the number, type, and quality of after market replacement and patch panels for the Tri-five Chevys. Consequently, rust on a prospective Tri-Five may have been repaired cosmetically with a new panel or a partial “patch” panel. The quality of how these panels were installed repairing the rust may be hard to determine in a finished car. Problems with less than proper installations may show up years after a purchase. Look for a “restored: car that has a photo journal of all phases of the “restoration” so you can witness first hand the quality of the job. The worst place for rust and usually the first place it shows up is in the floor pans, inner rocker panels, and body braces under the car. These problem areas are detected by pulling up carpeting or crawling under the car. Fixing rust in these area is more than just cosmetic, these are structural areas and require proper repair to restore the integrity of the car. In all but the rocker panel repairs, to be done properly requires the body to be lifted off of the frame, either partially or completely depending on the severity of the rust and needed repair. “Frame Off” is often the term seen or used in describing the process of separating the Body from the frame. It implies an in depth attempt to repair rust or restore the car. Using the term “Frame Off” is no guaranty that the repair or refinishing of the undercarriage of any car was properly done. It only describes the process of the repair. Once again look for photo documentation of the “Frame Off ” process. If you are paying someone to restore your Tri-five make sure it is photo documented. Ask questions before the process begins. Inquire about details of how the paint and rust are going to be removed, ie. blasting, type of medium, wire brushing, sanding etc. Ask what type of welding process is going to be used, electric, electric spot, gas braze or steel fill. Ask what type of refinishing is going to be done, etch, rust converter, primer, final coat. Each process and product has pluses and minuses. Some products and methods are not compatible. Clearly there are some products that have a better track record than others. Clearly, not all craftsmen or craftswomen are created equally.

Bruce